cDNA cloning of cytochrome P-450 related to P-450p-2 from the cDNA library of human placenta. Gene structure and expression.
We have isolated and analyzed cDNA (designated P-450HP cDNA) clones from a human placenta cDNA library, using the cDNA for rabbit pulmonary cytochrome P-450p-2, a prostaglandin omega-hydroxylase, as a hybridization probe. The cDNA obtained encoded a polypeptide comprising 511 amino acids with a calculated molecular mass of 58987 Da, and the amino acid sequence similarity with P-450p-2 and rat liver laurate omega-hydroxylase (P-450LA omega) was only about 50%. RNA blot analysis showed that the mRNA hybridizable with the human P-450HP cDNA was inducibly expressed 3-5-fold in rabbit small intestine and lung by gestation, but the expression remained constant in rabbit liver and kidney. This mode of expression was quite different from that of P-450p-2 and P-450LA omega. Interestingly, the mRNA hybridized with the cDNA of P-450HP was found to be expressed in all the human tumor tissues so far examined, in sharp contrast with the facts that almost all the other species of P-450s are known to disappear in the tumor tissues. Taken together, the deduced hemoprotein termed P-450HP dose not seem to be the human counterpart of rabbit P-450p-2 or rat P-450LA omega, and is presumably a new member of the P-450 family including P-450p-2 and P-450LA omega. Furthermore, the corresponding genomic DNA was also cloned and analyzed. The gene of P-450HP spanned 18.8 kb and was separated into 11 exons by 10 introns whose locations were completely different from those of P-450 genes so far determined.
Yokotani
N
N
Department of Chemistry, Faculty of Science, Tohoku University, Sendai, Japan.
Sogawa
K
K
Matsubara
S
S
Gotoh
O
O
Kusunose
E
E
Kusunose
M
M
Fujii-Kuriyama
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D005091:Exons; D005260:Female; D015870:Gene Expression; D005796:Genes; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D012333:RNA, Messenger; D004247:DNA; D003577:Cytochrome P-450 Enzyme System